• WASTE MANAG£ M IENT

Via UPS GROUND IZ2WXI070399455 1 14

August 13, 2012

Mr. Timothy A. Harbaugh, P.E., DEE Executive Director County of Kane Department of Facilities, Development and Environmental Resources 719 Batavia Avenue Geneva, Illinois 60134

Re: Settler's Hill RDF Proposed End-Use Redevelopment Plan

Dear Tim:

WASTE MANAGEMENT

Clmed Site Management Group 720 E. Butterfield Rd. Lombard, IL 60148 (6,0) 572-8800 (6,0) 21 8-1596 Fax

On behalf of Waste Management of Illinois, Inc. (WMIL), I would like to thank you and the County Board for sharing the proposed end-use plan for the Settler's Hill RDF and Midway Landfill complex, and affording WMIL an opportunity to provide some preliminary comments. While WMIL has been aware of the County's recreational development goals for some time, as these efforts come closer to fruition, WMIL is prepared to address issues of mutual concern that may arise as the County advances its plan.

As we have discussed previously, WMIL is concerned about how the redevelopment of the Settler's Hill landfill will affect the shared obligations of WMIL and the County with respect to the facility'S various permit and regulatory compliance requirements during the remainder of the facility's post-closure care period. As you are aware, the duration of WMIL's obligations are predicated, in part, on the period of time that the facility continues to generate landfill gas. Therefore, WMIL will be concerned about how the end-use redevelopment plan may affect methane production, monitoring, collection and control, as well as other operational concerns as described more fully below.

Upon receipt of the County's conceptual plan, WMIL asked Weaver Boos Consultants, an experienced solid waste consulting firm, to evaluate the County's proposed end-use redevelopment plans and identify areas of potential conflict between the post-closure care obligations and the County's proposed redevelopment plans. The following is a summary of their initial findings, although this is not intended to represent all of the issues that the County may encounter during the facility's redevelopment. We have broken this out by key site/environmental management areas.

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Mr. Timothy A. Harbaugh, P.E., DEE County of Kane August 13,2012 Page 2 of5

Leachate Management / Collection System

Proposed plan elements should be located away from underground storage tanks (UST), leachate risers and manholes, and leachate force mains (please refer to enclosed site diagram). Proposed plan elements should allow for year-round service vehicle and tanker truck access to pump the leachate USTs, and perform periodic maintenance. Excavation near USTs may require additional efforts to protect the structural integrity of the USTs and associated piping, and to safeguard the cathodic protection systems. Modification or relocation of any leachate UST, collection point, or force main will require IEP A permit modification. Location and access to any UST must be kept secured with access limited to maintenance personnel only.

Gas Collection & Control System / GCCS Monitoring

Proposed plan elements should be located away from gas collection and control system (GCCS) headers and laterals, where possible (please refer to enclosed site diagram). Proposed plan elements should allow for year-round service vehicle access to the GCCS and landfill gas monitoring probes. Periodic access must be available for drill rigs and haul trucks to drill gas extraction wells, move waste offsite, and deliver well construction materials. All aboveground GCCS components (extraction wells, valves, risers, sumps, etc.) must be enclosed within aboveground protective structures or in belowground vaults, and locked to maintain security. These structures may require periodic resetting as the landfill settles. Periodic re-grading of landfill gas piping may be necessary due to settling, and will require accommodations for deep and shallow excavation throughout the project area. Careful planning will be necessary to avoid conflicts between the proposed new access road and existing GCCS piping installed along the east edge of the landfill. Gas monitoring probes may need to be cut to ground level and flush-mounted. Some gas monitoring probes may have to be relocated to accommodate some plan elements. Relocation will require an IEP A permit modification. Permit-required periodic surface emission monitoring is required and must be performed on a pre-defined grid pattern across the landfill footprint, within the proposed plan area. Periodic and future decommissioning of gas extraction wells will require excavation across the landfill footprint, within the proposed plan area. Controlled access must be maintained to and around the Gas-to-Energy facility, and safety and noise setbacks may be necessary around the power plant. A security plan to protect all GCCS and monitoring system features will need to be developed as the public is allowed access to the facility.

Mr. Timothy A. Harbaugh, P.E., DEE County of Kane August 13,2012 Page 3 of5

Groundwater Monitoring

Proposed plan elements should be located away from groundwater monitoring wells. Relocating ground monitoring wells will require !EPA permit modification. Year-round access to groundwater monitoring wells must be maintained for service vehicles, drill rigs and water trucks, to perform periodic monitoring and maintenance. Decommissioning of groundwater monitoring wells will require excavation within the proposed plan area.

Surface Water Management System

Enlargement of ponds and construction of water quality features will require further study to determine any limitations due to permits, proximity to waste boundaries, or impacts to facility surfacewater and groundwater management systems, as well as hydrogeologic conditions. Any modification of the dam along the northern edge of the northwest pond will require a professional engineer sign-off and likely require DNR approval. Redirecting and/or incorporation of the Elfstrom Sports Complex stormwater management system onto the Settler's Hill facility will require an !EPA permit modification. Construction of an underground stormwater control system may be required in order to implement the Fishing and Ice Skating Ponds. The surfacewater management system must be constructed and maintained in compliance with the !EPA-issued RCRA and NDPES stormwater permit. All proposed surface water features in close proximity to the landfills must be engineered and lined to prevent water infiltration into the landfill. The northwest ponds proposed for redevelopment as Fishing Ponds are currently used as a source of irrigation water by the Golf Course. Consideration should be given to developing a plan to redirect effluent from the City of Geneva WWTP into this pond in order to expand its irrigation capacity, and utilize the pond to irrigate the Elfstrom Sports Complex as well.

Final Cover & Vegetation Management

Any grade changes on the final cover must be accomplished by adding fill soil. No cuts (grade reduction) can be allowed on the landfills. When placement of fill is necessary, the existing topsoil must be removed and filling accomplished with fine-grained, cohesive soils. The topsoil can then be replaced and reused to establish the required vegetative cover. Due to the many complications and added expense that can arise from irrigating a golf course or other recreational features built on a landfill, irrigation should not be permitted over portions of the landfill not equipped with a geomembrane liner. Irrigating over a

Mr. Timothy A. Harbaugh, P.E., DEE County of Kane August 13,2012 Page 4 of5

geomembrane liner may be acceptable depending on site conditions such as topography, and thickness and nature of the protective and vegetative soil cover. Excessive or prolonged irrigation over a geomembrane can lead to slope failure. Experienced soils and solid waste facility design engineers must be consulted during the planning of irrigated features on the landfill cap. Rutting along Mountain Bike and Cross Country Trails may encourage channeling of surfacewater and subsequent erosion. Adequate design elements must be incorporated to avoid need for ongoing maintenance and remediation. WM can provide an example where this end use is being implemented on a closed landfill. Planting of trees, bushes or other vegetation having deep or tap-roots cannot be permitted on the final cover of the landfill. Any plantings having significant root systems will need to be setback a minimum 75 feet from the edge of the landfill.

Site Access & Safety

All-season access for emergency vehicles and equipment must be maintained at all times. Perimeter drainage, and ditches, swales or ground depressions of any type, may pose a danger to sledding. Adequate run out areas and ground maintenance should be incorporated to prevent sledders from entering such features at a high rate of speed. Steep grades on the landfill pose considerations for speed and balance and should be factored into the detailed planning of all proposed amenities. All roads should be constructed to accommodate the weight of 6,000-gallon I8-wheel tanker trucks, in a~dition to the standard requirements for fire and life safety vehicle access. Access to all areas of the landfill must be maintained to allow for the delivery of soil using I8-wheel dump trucks, to fill depressions caused by differential settlement of the waste. Slopes around all existing ponds and stormwater conveyance structures must be evaluated; water features must be designed to allow persons and animals to extract themselves from these water features.

General

The integrity of the final cover system cannot be compromised in the construction of amenities atop the landfill. Provisions will need to be made for any structure or amenity to accommodate the potential for differential settlement. Structures or significant amenities planned for construction in close proximity to the landfill will likely require competent geotechnical investigation and foundation design.

This summary is not intended to represent all of the issues that may be encountered during the facility's redevelopment, but serves to highlight those than can be anticipated at this time and which should be considered as the plans and economics of site redevelopment are studied

Mr. Timothy A. Harbaugh, P .E., DEE County of Kane August 13,2012 Page 5 of5

further. As a practical matter, the plan should strive to avoid potential conflicts to the greatest extent possible, and planners should be reminded to not overlook the unique conditions, requirements and restrictions associated with the care and management of closed landfills. Although WMIL is not in a position to approve or disapprove of the County's redevelopment plans, we may have additional comments or input on future iterations of the end-use plan.

Kane County and WMIL have enjoyed success working together to serve the interests of the County, the Forest Preserve District, the communities of Batavia and Geneva, and the citizens of the county and surrounding area. In this spirit, it is important that all parties recognize the obligations and responsibilities that both the County and WMIL share to manage and maintain the closed landfill in a manner that will ensure public safety and health, as well as compliance with the permits and regulations that will remain in effect for decades to come.

WMIL looks forward to continuing to work with the County and its land planners to harmonize the post-closure and public safety obligations with the County's proposed end use objectives.

Please feel free to call or email me if you have any questions.

Respectfull y,

~.AN~M~~ OF ILLINOIS. INC.

Roderic S. Stipe, CHMM, QEP District Manager Closed Site Management Group

Enclosure

cc: Jack Dowden